ONVIF Profile T and H.265: the evolution of video compression

In today’s market, efficient use of bandwidth and storage is an essential part of maintaining an effective video surveillance system. A video management system’s ability to provide analysis, real time event notifications and crucial image detail is only as a good as the speed and bandwidth of a surveillance network.

In the physical security industry, H.264 is the video compression format used by most companies. Some companies also employ H.264 enhancements to compress areas of an image that are irrelevant to the user at a higher ratio within a video stream in order to preserve image quality for more important details like faces, license plates or buildings. The H.265, H.264’s successor, will be increasingly used for compression in the future. Some companies are already using H.265 in their cameras and video management systems, while a host of other manufacturers are certainly preparing for its broader adoption in the years to come.

Reduced bandwidth and storage requirements are the primary benefits of video compression technologies. In some cases, H.265 can double the data compression ratio of H.264, while retaining the same quality. Increased compression rate translates into decreased storage requirements on hard drives, less bandwidth usage and fewer switches – all of which reduce overall costs of system ownership. H.265 compression delivers a lower bitrate than H.264, which is relevant to end users and integrators because the lower bitrate reduces strain on hardware and can reduce playback issues.

It’s very important that the compression format that is used is supported in all of the different components of a system: cameras, desktop computers on which the VMS is running and the VMS itself. It is also good for end users and integrators to understand the basics of video compression. Having a basic understanding of compression allows users to tweak settings to reduce bandwidth usage even more. Many cameras come with default settings that can be changed to ultimately reduce costs.

In the physical security industry, ONVIF is working to incorporate into its specifications the use of new formats such as H.265 but is not directly involved in developing the compression standards themselves. With Profile T, the new ONVIF video profile released will employ a new media service that is compression agnostic.

This means that it can support new video compression formats, including H.265, as well as new audio compression formats, with the ability to include new video and audio codecs as needed in the future without having to redesign its media service. Standardisation organisations that are directly addressing new compression standards include the International Telecommunication Union (ITU), the Moving Picture Experts Group (MPEG) and a joint commission of the International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC), which is addressing the coding of audio, picture, multimedia and hypermedia information. Other compression formats on par with H.264 and H.265 are being developed by companies such as Google.

Using products that employ H.265 compression will reduce costs through bandwidth reduction, as will changing default settings on cameras, which are often conservative. Having a basic understanding of compression formats and how to tweak camera factory default settings also gives integrators the ability to further reduce bandwidth for added costs savings and increased system performance. It is also worth noting that H.265 enhancements will likely be developed by camera manufacturers to further reduce bandwidth, as was the case with H.264. These enhancements will analyze which parts of an image are most important and adjust local levels of compressions accordingly.

While H.265 itself is ready for prime time, its value as a tool for IP-based surveillance systems is dependent on support for the codec in all parts of the system – the VMS, server hardware, graphics cards and camera. Though widespread H.265 adoption is predicted, providers of these components are jumping on the H.265 bandwagon at different rates of speed.

ONVIF is including support for H.265 in its new video profile, Profile T, because it believes it will become the most widely used compression format and ONVIF recognises the need to anticipate that migration as a future need of the industry. The new media service, which will be implemented with Profile T, will be future-proof in that when new compression formats are released in the future, ONVIF can adopt them very quickly. That flexibility will definitely help integrators.